The easiest way is probably to just embed them as base64-encoded data:
using Dash, DashHtmlComponents, Base64
app = dash()
app.layout =
html_div([
html_h1("embedded image", style=(textAlign = "center",)),
html_img(src="data:image/png;base64,$(open(base64encode, "/path/to/file.png"))"),
])
run_server(app, "0.0.0.0", 8080)